Folic acid is a necessary component of the diet of pregnant women in order to prevent neural tube defects.
I think the answer might be Phospholipids but I am not sure
J-shape curve
J-shape curve is a curve that shows the population density of an organisms as they increase rapidly in a logarithmic or exponential form but abruptly stops due to environmental resistance. Thus, the population rate is largely determined by the biotic potentials and size of the population. However, exponential growth produces J-shaped curve.